1. Field of the Invention
This invention relates to microdots and, more particularly, to a novel, composite microdot and method wherein different types of composite layers are selectively affixed to the microdot to provide the microdot with various, preselected features such as enhanced visibility, camouflage, magnetic attraction, controlled buoyancy, and controlled biodegradation, to name several.
2. The Prior Art
Microdots, as the name implies, are small, usually less than about two millimeters in diameter, discs cut from a plastic substrate. Each microdot is configured to carry a unique identification feature such as a preselected color or a specific serial number to enable the subsequent finder of the microdot to identify the origin of the microdot. In one application, the microdot is imprinted with a specific serial number and is accompanied by several hundred or even thousands of identical microdots. These microdots are then placed discretely and even openly at numerous locations on various items of personal property on the premise that one or more of these microdots will be subsequently retrieved and thereby reveal the correct ownership of the item of personal property. The principle concept is that it is virtually impossible for a miscreant to remove all the microdots from the item. Further, some microdot systems are designed to allow a portion of the microdots to be dislodged during transit to thereby leave a trail of microdots which provide credible evidence as to the prior locations of the item, thus aiding in the apprehension of the miscreant and any cohorts.
Several microdot technologies are known in the art. Perhaps one of the earliest references in this field is that of Dillon (U.S. Pat. No. 4,243,734 which discloses a microdot configured as a square having a side dimension in the nature of 0.007 inch. Each microdot includes the indicia of the particular owner.
Another identification system that uses a plurality of small labels, not microdots, per se, is that of Krietemeier et al (U.S. Pat. No. 4,763,928). This disclosure relates to small tags which are cut from a strip of plastic but releasably held on a substrate to allow the person applying the tags to individually retrieve a tag from the plastic strip and mount it to the item.
From the foregoing it is clear that various attempts have been made to provide a microdot identification system for an item of personal property. However, there are numerous instances where it would be desirable to have a microdot that could be used not only to mark items of personal property but also in applications not involving an item of personal property. It would also be advantageous to provide a microdot system, where the microdot is readily visible, where the microdot is camouflaged, has a preselected buoyancy, can be attracted to a magnetic field, or even will biodegrade after a period of time. Such a novel apparatus and method is disclosed and claimed herein.